Ramp load slider

ABSTRACT

An apparatus and method is presented for controlling initial load and unload wear on a slider by using a trailing edge extender. A slider for supporting a transducer proximate to a recording medium is disclosed. The slider includes a trailing edge extender positioned on a trailing edge to allow additional controlled wear to occur before a substrate of the slider contacts the recording medium. The trailing edge extender can be positioned at an outer corner on the trailing edge of the slider and at a transducer pad on the trailing edge of the slider. The trailing edge extender can include a depth of the step depth, cavity depth, or air bearing surface level depth. The method includes fabricating a trailing edge extender positioned on a trailing edge to allow additional controlled wear to occur before a substrate of the slider contacts the recording medium.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application claims the benefit of an earlier filedU.S. Provisional Application Ser. No. 60/193,557, which was filed onMar. 30, 2000, and is entitled “IMPROVED RAMP LOAD SLIDER.”

BACKGROUND

[0002] In magnetic disc drives, ramp load disc heads contact the discstorage media while the heads are loaded onto the media. FIG. 1 shows aschematic of a typical recording head slider 100. The slider includes atrailing edge 101 and a disc head 102. FIG. 2 shows a picture of thetrailing edge comer of the center pad 103 of such a slider after a largenumber of load and unload cycles 200. In FIG. 2, the comer 201 haschanged in height after it is worn during ramp loading. The corner 201has worn off at approximately the angle of the static attitude of theslider. The wear is due to the large (relative to flying attitudes)pitch and roll static attitude of typical parts.

[0003] The wear shown in FIG. 2 is on the trailing edge center pad. Theslider body comers can acquire similar wear under even modest rollstatic attitude conditions. The wafer substrate 204 becomes the greaterpart of the slider body 200. The head overcoat 205, typically aluminumoxide, protects the head from environmental chemical attack.

[0004] During the initial load and unload cycles, media damage can occurwhere the slider contacts the media. This damage can decrease as thenumber of load and unload cycles increases, until at some point there isno additional wear with additional cycles. At this point, the head hascompletely “run in.”

[0005] As the slider approaches the disc, there is typically nosubstantial air bearing effect from the comer of the slider or on thecenter pad because the static attitude angles are too large. There istypically no real opportunity for an air bearing to form. As the sliderwears, however, a flat area 201 relative to the disc during loading canform. This flat can grow until it forms enough of an air bearing, whichcan result from the air compression due to the static attitude angles.This air bearing is adequate when the force on it is enough to overcomethe static torque placed on the slider by the suspension. At this point,the loading on the disc becomes relatively benign because the slider canbe loaded without any substantial solid-to-solid contact. If the headand disc interface has survived this long, it typically lastsindefinitely.

[0006] As in FIG. 2, the aluminum oxide 205 forming the trailing edge ofthe slider 202 is of finite thickness. If there is too much staticattitude or too little disc speed for an air bearing to form, thealuminum oxide 205 will continue to wear until the much harder slidersubstrate 204 begins to contact the disc. It is desirable to minimizealuminum oxide thickness in recording head wafers to reduce cost andreduce pole tip thermal expansion. The center part of the aluminum oxide202 is already etched away resulting in even less aluminum oxide to wearin. Therefore, it is desirable to find a way to control more effectivelythe ramp load and unload wear on the slider.

SUMMARY

[0007] The present invention relates to controlling initial load andunload wear on a slider. In particular the present invention relates toa trailing edge extender for controlling initial load and unload wear ona slider.

[0008] In one aspect of this invention, a slider for supporting atransducer proximate to a recording medium is disclosed. The sliderincludes a trailing edge extender positioned on a trailing edge. Theextender allows additional controlled wear to occur before a substrateof the slider contacts the recording medium. The trailing edge extendercan be positioned at an outer corner on the trailing edge of the slider.The trailing edge extender can be positioned at a transducer pad on thetrailing edge of the slider. The trailing edge extender can include adepth of the step depth, cavity depth, or air bearing surface leveldepth.

[0009] The slider can include a second trailing edge extender positionedon the trailing edge of the slider. This second trailing edge extendercan be positioned on an opposite side of the first trailing edgeextender on the trailing edge of the slider. The trailing edge can bemade of a material or combination of materials such as aluminum oxide,diamond-like carbon, aluminum nitride, and silicon carbide.

[0010] In another aspect of this invention, a method for fabricating aslider for supporting a transducer proximate to a recording medium isdisclosed. The method includes fabricating a trailing edge extenderpositioned on a trailing edge. The extender allows additional controlledwear to occur before a substrate of the slider contacts the recordingmedium. The fabrication of the trailing edge extender can includedepositing a ridge over a dice cut. The fabrication of the trailing edgeextender can also include dicing a rowbar to form a partial ridge.

[0011] The details of one or more embodiments of the invention are setforth in the accompanying drawing and the description below.Implementations can provide advantages such as improved control of theramp load and unload wear on the slider.

DESCRIPTION OF DRAWINGS

[0012]FIG. 1 is a drawing of a slider.

[0013]FIG. 2 is a picture of a worn slider head.

[0014]FIG. 3 is a drawing of a slider with the new trailing edgeextender positioned on the outside edge of the slider.

[0015]FIG. 4 is a drawing of a slider with the new trailing edgeextender positioned next to the center pad of the slider.

[0016]FIG. 5 is a drawing of a slider with the new trailing edgeextender positioned at the air bearing level.

DETAILED DESCRIPTION

[0017] The present invention relates to controlling initial load andunload wear on a slider. In particular the present invention relates toa trailing edge extender for controlling initial load and unload wear ona slider.

[0018]FIG. 3 shows a slider 300 with extensions to the conventionalaluminum oxide overcoat at the trailing edge cavity corners 301. Thetrailing edge extenders 302 can allow additional controlled wear tooccur on the slider when it runs in against the media before thesubstrate begins to contact the media. The size of the extenders can betailored to the wear characteristics of both the extender and discmedia. The extension can be made of aluminum oxide, diamond like carbon,or any alternative wear material. If the overcoat material on the waferis very thin then a corner pad may be required. This corner pad can beof any tribological material that can be patterned onto the completedwafer. The general geometry of the trailing edge extensions 302 in FIG.3 is purely schematic. It may be desirable not to have a complete “hill”on the trailing edge comer 301 top to bottom. One may want to simplypattern bumps on the comers of the slider.

[0019] Features fabricated at the wafer level as is shown in FIG. 4 cansimilarly protect the center pad 402. At the trailing edge of the etchedstep 401 on the comers of the center pad 402, two posts 403 arefabricated on the wafer. These posts 403 can be made of aluminum oxideor some other tribological material that can be patterned on thefinished wafer. The center pad 402 typically is placed as close aspossible to the trailing edge 401 of the slider, making it difficult torecess it. These pads are similar in function to the trailing edgeextenders 302 in FIG. 3, but are likely to have different geometry.

[0020]FIG. 5 shows an alternative embodiment with the trailing edgeextenders 503 positioned at the air bearing level of the slider 500. Thetrailing edge extenders can be positioned at different depths along theslider. Examples of these depths include the cavity depth of FIG. 3,step depth of FIG. 4, and air bearing surface level of FIG. 5. Otherdepths or combinations of depths can be similarly used to protect theslider.

[0021] The trailing edge extenders can be fabricated on the trailingedge at the step depth, cavity depth, or air bearing surface level toallow additional controlled wear to occur before a substrate of theslider contacts the recording medium. The trailing edge extenders can bedeposited on a completed wafer as a set of ridges over the dice cut.When the wafer is sliced, individual sliderlevel ridges are formed. Theridges may or may not span the dice alley. There can be one ridge perdice alley or two spanning a disc alley in the uncut wafer.

[0022] Cylindrical posts along the center pads can also be deposited andsubsequently machined to slice, lap, and mill the slider into theresulting shape.

[0023] The trailing edge extenders can be fabricated using materials orcombination of materials such as aluminum oxide, diamond-like carbon,aluminum nitride, and silicon carbide. Other similar materials can alsobe used.

[0024] Although FIGS. 1, 3, 4, and 5 show the transducer at the centerof the slider body, the transducer may be located at different locationsalong the trailing edge, such as at the side rails or off-center alongthe trailing edge. The positioning of the transducer would not affectthe functioning of the trailing edge extenders.

What is claimed is:
 1. A slider for supporting a transducer proximate toa recording medium, the slider comprising: a trailing edge extenderpositioned on a trailing edge, wherein the extender allows additionalcontrolled wear to occur before a substrate of the slider contacts therecording medium.
 2. The slider of claim 1, wherein the trailing edgeextender is positioned at an outer comer on the trailing edge of theslider.
 3. The slider of claim 1, wherein the trailing edge extender ispositioned at a transducer pad on the trailing edge of the slider. 4.The slider of claim 1, wherein the trailing edge extender comprises adepth selected from the list consisting of the step depth, cavity depth,and air bearing surface level depth
 5. The slider of claim 1, furthercomprising a second trailing edge extender positioned on the trailingedge of the slider.
 6. The slider of claim 5, wherein the secondtrailing edge extender is positioned on an opposite side of the firsttrailing edge extender on the trailing edge of the slider.
 7. The sliderof claim 1, wherein the edge extender comprises on e or more materialsselected from this list consisting of aluminum oxide, diamond-likecarbon, aluminum nitride, and silicon carbide.
 8. A method forfabricating a slider for supporting a transducer proximate to arecording medium, the method comprising: fabricating a trailing edgeextender positioned on a trailing edge, wherein the extender allowsadditional controlled wear to occur before a substrate of the slidercontacts the recording medium.
 9. The method of claim 8, wherein thestep of fabricating a trailing edge extender further comprisesdepositing a ridge over a dice cut.
 10. The method of claim 8, whereinthe step of fabricating a trailing edge extender further comprisesdicing a rowbar to form a partial ridge.
 11. The method of claim 8,wherein the fabricated trailing edge extender is positioned at an outercomer on the trailing edge of the slider.
 12. The method of claim 8,wherein the fabricated trailing edge extender is positioned at atransducer pad on the trailing edge of the slider.
 13. The method ofclaim 8, wherein the fabricated trailing edge extender comprises a depthselected from the list consisting of the step depth, cavity depth, andthe air bearing surface level depth.
 14. The method of claim 8, furthercomprising fabricating a second trailing edge extender positioned on thetrailing edge of the slider.
 15. The method of claim 14, wherein thefabricated second trailing edge extender is positioned on an oppositeside of the first trailing edge extender on the trailing edge of theslider.
 16. The method of claim 8, wherein the edge extender comprisesone or more materials selected from the list consisting of aluminumoxide, diamond-like carbon, aluminum nitride, and silicon carbide.
 17. Aslider for supporting a transducer proximate to a recording medium, theslider comprising: a slider body; and a trailing edge extender means forallowing additional controlled wear to occur before a substrate of theslider contacts the recording medium.